prefill username in login

src/app/auth/login/device/page.tsx

@@ -7,22 +7,35 @@ import { cache } from "react";
 export const dynamic = "force-dynamic";
 
 type Props = {
-    searchParams: Promise<{ code?: string }>;
+    searchParams: Promise<{ code?: string; user?: string }>;
 };
 
+function deviceRedirectSearchParams(params: {
+    code?: string;
+    user?: string;
+}): string {
+    const search = new URLSearchParams();
+    if (params.code) search.set("code", params.code);
+    if (params.user) search.set("user", params.user);
+    const q = search.toString();
+    return q ? `?${q}` : "";
+}
+
 export default async function DeviceLoginPage({ searchParams }: Props) {
     const user = await verifySession({ forceLogin: true });
 
     const params = await searchParams;
     const code = params.code || "";
+    const defaultUser = params.user;
 
     if (!user) {
-        const redirectDestination = code
-            ? `/auth/login/device?code=${encodeURIComponent(code)}`
-            : "/auth/login/device";
-        redirect(
-            `/auth/login?forceLogin=true&redirect=${encodeURIComponent(redirectDestination)}`
-        );
+        const redirectDestination = `/auth/login/device${deviceRedirectSearchParams({ code, user: params.user })}`;
+        const loginUrl = new URL("/auth/login", "http://x");
+        loginUrl.searchParams.set("forceLogin", "true");
+        loginUrl.searchParams.set("redirect", redirectDestination);
+        if (defaultUser) loginUrl.searchParams.set("user", defaultUser);
+        console.log("loginUrl", loginUrl.pathname + loginUrl.search);
+        redirect(loginUrl.pathname + loginUrl.search);
     }
 
     const userName = user
@@ -37,6 +50,7 @@ export default async function DeviceLoginPage({ searchParams }: Props) {
             userEmail={user?.email || ""}
             userName={userName}
             initialCode={code}
+            userQueryParam={defaultUser}
         />
     );
 }